Stephen Harris <lists@xxxxxxxxxx> writes: > It's vacuumed every night after the updates. There are minimal (zero, > most days) updates during the day. As I mentioned earlier, nightly we do: > for host in list_of_hosts > delete from sweep_users where hostid=host > for user in users_for_host > insert into sweep_users .... > vacuum analyze sweep_users Hmm ... no overlap between the sets of users for different hosts? This looks like the worst-case bloat should be 2X (at most one dead and one live row per user), but the numbers you are reporting --- particularly the unused-item-pointer count --- show clearly that at some point there was a bloat factor of more than 100, ie, there had been at least 100 complete replacements of the table without a vacuum. Perhaps that vacuum step was only recently added to this script? > You recommend a "cluster sweep_users" before the vacuum, then? I wouldn't think you need to do it every night, it's just a one-time fix. regards, tom lane
